2015. The last era when magic was still established. The Humane Continuity Guarantee Agency, Caldea, observes a world that can not be seen only with magic, a world that can not be measured only with science, and conducts research day and night to prevent the decisive extinction of humanity, with a preservation that preserves human history stronger than anything else Continued. One day, the future territory that had been continuing observations in Caldea disappeared, and calculations showed that humanity would be extinct in 2017-or no, it was proved. Meanwhile, "unobservable areas" suddenly appear in various places in history. Chaldea assumes that this is the cause of human extinction, and issues a mission to search for and elucidate singularities, or to destroy, "Search for the Holy Grail" --- Grand Order. Tachika and Mash, who were assigned the duties, went to a singularity that was confirmed in 1273. The singularity itself was becoming a "history that should not exist."